World Health Day, celebrated each year on the 7th of April, marks the founding, in 1948, of the World Health Organisation (WHO), and highlights a priority area of public health concern. Here at ARKive, we decided to find out more about the links between species and human health, and show you just how important the conservation of biodiversity is to the advancement of medical science.

Species and medicine

When was the last time you had a headache and reached for some aspirin to relieve the pain and pressure? Or perhaps you’ve had a bacterial chest infection over the cold, harsh winter and were prescribed some antibiotics to get rid of it? Well, you have the wonderful plant and fungal kingdoms to thank for your recovery.

Aspirin is derived from a compound found in willow bark

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The antibiotic penicillin was discovered in a species of Penicillium soil fungus, while aspirin, an anti-inflammatory drug used to relieve minor aches and pains, was derived from a compound found in the bark of willow trees.

The Madagascar periwinkle has been instrumental in fighting cancer

The Madagascar periwinkle, also known as the rosy periwinkle, might sound like a pink marine mollusc, but it is, in fact, a very special plant species. Traditionally, the Madagascar periwinkle was used by healers to treat diabetes, but more recently it has provided the basis for the production of two incredibly important cancer-fighting drugs. One of these has helped increased the chance of surviving childhood leukaemia from just 10% to 95%. Plants are pretty awesome!

Another effective cancer-fighting drug has been derived from the Canadian yew tree

Vital venom

Plants aren’t the only species group to hide medicinal secrets, with chemical compounds being found in all sorts of unlikely places proving to be extremely useful in the treatment of various conditions. For instance, an anticoagulant drug, used to prevent blood from clotting, is based on the venom of a species of saw-scaled viper from Africa.

The venom from a species related to this Sind saw-scaled viper has been used to develop an anticoagulant

Healthy ecosystems, healthy humans

As well as presenting us with a whole host of compounds which could be used to formulate effective medicinal drugs, species are vital to our health and wellbeing in many other ways. We all know that trees produce life-giving oxygen, but there are several other roles that species play which help us out. Freshwater molluscs, for instance, provide an array of important services to the freshwater ecosystems in which they live, such as nutrient cycling and water filtration, which in turn are beneficial to human health.

Freshwater pearl mussel

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Indicator species

Wild species can also act as indicators of environmental problems such as pollution. The survival of dragonflies is highly dependent on the presence of healthy indigenous vegetation which provides oxygen and clean water for the developing insect, as well as a safe area for the dragonfly nymphs to transform into adults. The presence of chemical pollution, such as pesticides, nutrient run-off from agricultural areas and water contaminants from urban landscapes, could lead to dragonflies being absent from a given water body, which in turn is an early warning signal to us that there is a problem.

Dragonflies, such as this impressive emperor dragonfly, can act as important environmental indicators

Genetic health

Something which people might not often consider when thinking about health is genetic health. There are thousands of threatened species around the world suffering from a variety of factors including habitat loss, climate change and poaching, but the future of some species is placed in an even more precarious position as a result of a lack of genetic diversity in the population. One such species is the majestic and speedy cheetah. Low genetic variation in cheetahs, both captive and wild, means that these populations are particularly vulnerable to sudden environmental change and disease.

Cheetahs face many threats, including low genetic diversity

The charismatic Tasmanian devil is another species that is thought to be negatively affected by a lack of genetic variation. Due to the low diversity within the population, the Tasmanian devil is under increased risk from the devastating devil facial tumour disease (DFTD), as the bit of the genome required to reject the tumour-producing cells is not as prevalent or effective.

Tasmanian devil

Wildlife could provide more answers to a whole range of medical ailments, but with the current rate of extinction, these vital species could disappear before we’ve discovered them or unveiled their incredible secrets. Biodiversity conservation and wildlife management to avoid exploitation are both extremely important for many reasons, not least the potential for curing the currently incurable, and with further research into species and their fascinating properties, who knows what the future could hold?